Materials
The environment your application is going in will affect the material you choose. While additives can be applied to materials at the point of processing to enhance desired characteristics, knowing the material’s original state helps you make an informed decision.
With that in mind, let’s start with common materials for knobs and handles.
| Materials |
Pros |
Cons |
| Nylon |
- Most popular materials across all industries
- High-impact resistance
-Excellent resistance to most oils, fuels and greases
- Has good electrical insulating properties |
- Tends to absorb moisture from surroundings
- Can be attacked by strong acids, alcohols and alkalis |
| Phenolic |
- Cost-effective, lightweight
- Resistant to high impact, heat and wear, oils, fuels and greases
- Excellent corrosion
- Thermal and electrical resistance |
- A thermosets, hard and rigid, potentially fail in extremely high-vibration applications |
| Thermoplastic elastomer (TPE) |
- Often used as an overlay material to provide a soft, comfortable feel for the end user
- High-impact strength
- Excellent resistance to ozone and weathering
- Tear and abrasion resistance |
- Costly
- Vulnerable to heat aging |
| Polypropylene (PP) |
- Semi-rigid
- Resists most chemicals
- Heat and fatigue resistance |
- Poor UV resistance
- Oxidative degradation is accelerated by contact with copper |
| Low Density Polyethylene (LDPE) |
- Low-cost material and is semi-rigid
- Very tough and can be formulated to be weather resistant
- Provides good resistance to some chemicals and low water absorption |
- Without additives, LDPE does a poor job resisting the elements and is not resistant to stress |
| Aluminium |
- lightweight compared to other metals
- Can be made to almost any strength, and in cold weather, it becomes stronger
- Provides very good corrosion resistance
- Thermal and electrical conductivity |
Although its corrosion resistance is highly rated, it’s not as good as stainless steel |
| Stainless steel |
- Excellent for corrosion resistance
- Retains its strength in high temperatures
- Hygienic and non-porous
- Provides an aesthetic appearance, and as a metal, can be recycled |
- If electrical conductivity is important, look for alternative
- Cost more than plastics |
| Brass |
- Tough copper-zinc alloy
- Wear resistant and frequently used when low friction is required
- Excellent thermal conductivity |
- Oxidise when exposed to the air
- Soft compared to other metals
- More costly |
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| Pull Handles, Stainless steel |
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| Polypropylene Scalloped Handwheel |
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